Flexible printing plate clamping device

ABSTRACT

A plate cylinder of a printing machine has two separate fastening devices for thin flexible printing plates for various page sizes. One of the fastening devices is constructed for adjusting of both the circumferential and the lateral register of plates for various page arrangements in such a manner that the registering fastening device has a shaft comprises several individual parts which can be coupled and uncoupled for various page combinations whereby the shaft portions can be separately adjusted for circumferential and lateral register.

O United States Patent 1151 3,659,525 Woessner et al. [4 1 May 2, 1972 54] FLEXIBLE PRINTING PLATE 2,553,856 5 1951 Janke ..101/415.1 CLAMPING DEVICE 2,639,668 5/1953 Chase et al. ..l01/378 2,768,578 10/1956 Park et al 101/415.1 [72] lnventors: Richard Woessner, Fan-lawn; Jack Bryer, 2,813,306 H1958 Harless W101 [373 Paramus both of Dominic 2,915,010 12/1959 Crafts..... ...101/37s Bellerose, 3,410,211 11/1968 Grunig ..101/415.1 73 A i nee: Wood Indu tri I c. Pl 1' 1d, NJ. 55g s n am 1e Primary Examiner-Clyde [.Coughenour [22] Filed: Oct. 28, 1969 Anorney-Pennie, Edmond, Morton, Taylor and Adams [21] Appl.No.: 870,027 ABSTRACT 52 us. c1 ..101/415.1, 101/378 gzf gi z 3:12: 1 gg 511 1m.c1 ..B411 1/30, B4lf 13/16, B4lf27/06 P P 52 Field of Search ..101/415.1 37s one 'l devces adlusmg of both the c1rcumferent1al and the lateral reg1ster of plates for various page arrangements in such a manner that the register- [56] References cued ing fastening device has a shaft comprises several individual UMTED STATES PATENTS parts which can be coupled and uncoupled for various page combmations whereby the shaft portions can be separately adl,752,659 4/ l 930 Banzett l0l/4l5.l justed f i f ti l and lateral regimen 2,012,972 9/1935 Osborn ..101/4l5.l 2,038,320 4/1936 Swift 101/378 4 Claims, 8 Drawing Figures Patented May 2, 1972 2 Sheets-Sheet l Patented May 2, 1972 2 Sheets-She t 3 FIG. 7

BY JAM ewri/P Z FLEXIBLE PRINTING PLATE CLANIPING DEVICE BACKGROUND OF THE INVENTION The invention relates to plate cylinders of printing machines and particularly to fastening devices in such cylinders for attaching of thin, flexible printing plates thereto and for circumferentially and laterally registering of the plates thereon.

Plate cylinders for thin, flexible printing plates are known in the art, on which plates of the size of the entire length of the cylinder are fastened. There are also devices known on such plate cylinders by which thin plates of the width of a single page can be secured. However, in cases where the printed product of the machines is intended to have pages of various widths, the hitherto known plate clamping devices on the plate cylinders are either arranged for a full size of the various paper widths or for the size of individual page width. No arrangement of plate clamping devices for a variety of different page widths are known in which the individual component parts of at least one of the clamping devices, particularly for the register adjustment side, can be coupled or uncoupled and in which the uncoupled parts can be adjusted separately at the ends of the plate cylinder.

This invention solves the problem.

SUMMARY The invention comprises such novel features, construction arrangements, combinations of parts and improvements as may be shown and described in connection with the device herein disclosed by way of example only and as illustrative of a preferred embodiment. The advantage of the invention is to enable the user of the printing machine to produce signatures of different page widths and to make full use of the maximum possible paper web widths for the possible maximum number of pages thereon. The basic idea of the invention is to present individual clamping facilities for the necessary printing plates for the combinations of the diflerent page sizes and for having independent devices for register adjustments of these individual fastening facilities, which can be coupled'or uncoupled, as the case may be. Objects of the invention will be set forth in part hereafter and in part will be obvious herefrom or may be learned by practicing the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

It is an object of the invention to provide a first fastening bar in the plate cylinder of a printing machine, which comprises several parts for fastening of thin flexible printing plates of different sizes.

It is a further object of the invention to provide releasable couplings on at least two of the several parts of the first fastening bar in the plate cylinder for separating these parts.

Furthermore, it is an object of the invention to provide for devices for independent adjusting of both the circumferential and the lateral register of the plates which are attached to the several separated parts of the first fastening bar.

Another object of the invention is to provide a second fastening bar in the plate cylinder of a printing machine with independently spring-loaded, partly rotatable plate clamps thereon for tensioning the printing plates which are held by the first fastening bar.

Various further and more specific purposes, features and advantages will clearly appear from the detailed description given below taken in connection with the accompanying drawing which forms part of the specification and illustrates merely by way of example one embodiment-of the device of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the following description and in the claims, parts will be identified by specific names for convenience, but such names are intended to be as generic in their application to similar parts as the art will permit. Like reference characters denote like parts in the several figures of the drawing, in which:

FIG. 1 is an overall view of the plate cylinder of an offset printing machine;

FIG. 2 is a schematic layout of the, various paper web widths which can be used in conjunction with the plate cylinder shown in FIG. 1;

FIG. 3 shows a plan view of the left side end of the plate cylinder shown in FIG. 1;

FIG. 4 is a longitudinal partial section of the center portion of the plate registering bar of the cylinder shown in FIG. 1, partly broken away; shown in an enlarged scale;

FIG. 5 is a radial secu'on of the plate cylinder shown in FIG. 1, taken along the line 5-5 thereof;

FIG. 6 is a radial section of the plate cylinder shown in FIG. 1, taken along the line 6-6 thereof;

FIG. 7 is a partial section taken along the line 7-7 on FIG.

FIG. 8 is a partial view of the section of the clamping shaft shown in FIG. 5, illustrating in an enlarged scale the detail of the trailing key.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring'now in more detail to the drawing illustrating a preferred embodiment by which the invention may be realized, there is in FIG. 1 a printing plate cylinder 10 having a solid body 11 with two axial grooves l2, l2 milled therein (see also FIGS. 5 and 6). At both ends of body 11 are bearer rings 13, 13'. Insert parts 14, 15, 16, respectively, are placed in grooves 12, 12'. Two shafts 17, 18 (and 17, 18' correspondingly) are rotatably located in inserts 14, 15, 16 in bearing bushings 19, 20, as seen in FIGS. 3 and 4. Shaft 17, 17' is divided into three sections 21, 22, 23 which are axially aligned by pilot ends 24, 25, in pilot bores 26, 27, as shown in FIG. 4, which shows the center section 22 in an enlarged scale. Sections 21 and 22, and sections 23 and 22 can be coupled by clamping mechanisms 28, 29, in order to facilitate the various plate combinations shown in FIG. 2. A plurality of plate end supporting plates 30 are mounted in juxtaposed arrangement on shaft sections 21, 22, 23, as shown in FIGS. 1, 4 and 5 Leaf spring blades 31 are also attached to supporting plates 30 so that the head ends of the printing plates can be easily inserted and be held in place on the latter.

In order to register the printing plates both circumferentially and laterally, the free ends of both shafts 21, 23, have adjustable registering devices attached thereto, as shown in FIGS. 3 and 6. A split collar 32 which has a limited number of gear teeth 33 cut on a part of the circumference thereof, is keyed on the free end of shaft 21 (and 23, as well). A small gear rack 34 is arranged to engage teeth 33 for rotating collar 32 and thus shaft part 21, as shown in FIG. 6, by the small amount which is needed for registering of the plates secured on this shaft part. Gearrack 34 has a threaded bore through which a screw 35 is threaded. Screw 35 is also threaded in the bottom part 36 of the bracket 37, but the diameter of the thread in bottom part 36 is different from the thread in the bore of rack 34. Thus a fine adjustment of this device is possible by virtue of the differential action of the two different threads. A compression spring 38 is placedunder gear rack 34, urging the same in a positive direction for eliminating a backlash between the teeth of rack 34 and the geared part of collar 32.

The mechanism for adjusting of the lateral register consist of a U-shaped shoe 39 which embraces apart of collar 32. Shoe 39 has a threaded bore for receiving a screw therein. A thrust washer 41 secures the axial position of screw 40. Turning of screw 40 clockwise or counter-clockwise will move shoe 39 in one or the other direction, respectively, and thus will shift the corresponding bar with the printing plates attached thereon in axial direction for adjusting of the lateral register. Each one of shafts 18 and 18' is also divided into three parts 42, 43, 44 which are coupled together in a tongue-and-groove fashion. A plurality of platetensioning members 45 are positioned in a side-by-side arrangement on shafts 18, 18' in such manner that each one of members 45 can rotate by a small amount independent of one another, but all members are attached toshafts 18, 18' by trailing keys 46 and thus can be moved simultaneously by rotating of shaft 18 from the plate unlocking position to a tensioning position. Members 45 consist of a double arm lever, the arm 46 carrying a bar 47 having a slot 48 for receiving the tail end of the printing plate, while the other arm 49 has a pushrod 50 hingedly attached to the end thereof. Pushrod 50 abuts against a plunger 51 which is under the pressure of a compression spring 52 contained in a bushing 53 in cylinder body 11 (FIGS. 1 and Shafts 18, 18' can be rotated from the outside of the bearer ring 13 by the intermediate gears 54, 55 and a short shaft 56 which passes below bearer ring 13. Shaft 56 has a hub 57 attached thereto on the outside face of cylinder (see FIG. 3). The arrangement of lever arm 49, push rod 50 and spring plunger 51 is such that shaft 18 can be rotated with the members 45 thereon from one end position over center into the other end position. In the first end position, bars 47 will abut against one side of the slot 58 in insert parts 14, 15, 16 for inserting the tail end of the printing plate into slot 48; in the second (over center) position springs 52 will tension the printing plates on cylinder body 11 and will keep the plates in the tensioned condition thereon by virtue of the trailing key arrangement.

OPERATION It is shown schematically in FIG. 2, that signatures of various page width and in various page numbers across the plate cylinder can be printed due to the construction of the plate fastening devices thereon. When signatures of certain page sizes are to be produced, the total length of the cylinder permits arranging of five plate of page size on the cylinder, corresponding to the paper web widths and arrangements 61 and 63 in FIG. 2. Clamping collar 28 of plate holding parts 30 is opened and clamping collar 29 is locked so that part 23 and third part 22 are operatively connected. Two printing plates, one carrying two pages and the other one carrying three pages are prepared by bending both the head ends and the tail ends off. The bent-off head ends are inserted in holding parts 30 and are held there by leaf springs 31. The plates are then wrapped around cylinder body 11 until the bent-off tail ends can be inserted in slots 48 of the tensioning sections 45 on shaft 18. Subsequently the plates are tightened on the cylinder by rotating shaft 18 so that the linkage arm 49 is moved over center whereafter springs 52 keep the plates in tight condition on cylinder 11. From the start of the operation, plates 30 are abutting against the inner edge of slot 58 in the cylinder inserts 14, 15, 16. This is considered the starting or reference position. Since the two plates on one side and the three plates on the other side can be independently set by the register setting mechanisms 32 on either face of cylinder body 11, it is possible to adjust the plate register more individually rather than to register one large printing plate which extends over the entire length of the cylinder. The individual tensioning sections are mounted on shaft 18 by keys 46 but keyways 60 in the sections are enlarged so that each one of the sections can follow up and adjust itself to the setting of the plates under the force of spring 52 of the over-center linkage. Similarly the lateral register adjustment of the plates can be performed by the screw mechanisms 39, 40 on either face end of cylinder 1 1.

By opening of clamping collar 29 and by locking of clamping collar 28 another printing plate arrangement can be made for another signature page size and paper web width, according to the schematic layout 62 in FIG. 2.

We claim:

1. In a rotary printing machine, a plate cylinder for substantially thin flexible printing plates of various sizes, said cylinder having end faces, said plates having a head end and a tail end, said cylinder comprising:

first adjustable means axially extending of said cylinder for i holding said head ends of said plates,

said first means comprising at least two independent parts,

second movable means axially extending of said cylinder for holding said tail ends of said plates, a said second means comprising a plurality of independent sections in a side by side arrangement, a spring-loaded over-center movable linkage on each one of said independent sections for tensioning of said printing plates around the periphery of said cylinder and a rotatable shaft axially extending of said cylinder for mounting said independent sections thereon by keys and for moving simultaneously said plurality of said independent sections from a starting position over the center of said linkage to the plate tensioning position,

and a third part of said first means intermediate said two independent parts and releasable clamping collars on said parts for coupling the latter together.

2. In a rotary printingmachine, a plate cylinder for substantially thin flexible printing plates of various sizes, said cylinder having end faces, said plates'having a head end and a tail end, said cylinder comprising:

first adjustable means axially extending of said cylinder for holding said head ends of said plates, said first means comprising at least two independent parts, second movable means axially extending of said cylinder for holding said tail ends of said plates,

said second means comprising a plurality of independent sections in a side by side arrangement, a spring-loaded over-center movable linkage on each one of said independent sections for tensioning of said printing plates around the periphery of said cylinder and a rotatable shaft axially extending of said cylinder for mounting said independent sections thereon by keys and for moving simultaneously said plurality of said independent sections from a starting position over the center of said linkage to the plate tensionin g position,

and each of said independent sections having a circumferentially enlarged keyway therein for permitting each one of said sections to rotate freely on said shaft through a substantially small angle for enabling said over-center linkage to move each one of said sections under said spring load for tensioning said flexible printing plates held on said sections.

3. In a rotary printing machine having a plate cylinder with end faces and bearer rings on said faces, said plate cylinder adapted to support thin flexible printing plates of various sizes where each of said plates has a head end and a tail end and where said cylinder comprises:

first rotatably adjustable plate holding devices having at least two independent sections extending axially of said cylinder for holding the head ends of said plates and by which the position of said head ends may be adjusted in circumferential and lateral directions with respect to said cylinder,

second rotatably movable plate holding devices extending axially of said cylinder for holding the tail ends of said plates where said second devices comprises: a plurality of independent individual members mounted on a common axially extending rotatable shaft in side by side arrangement, key means connecting said members to said common shaft so as to allow independent rotation thereof, a spring-loaded over-center movable linkage on each one of said independent members for tensioning said printing plates around the periphery of said cylinder whereby rotation of said common shaft will move said members together from a starting position over the center of said linkages to the plate tensioning position.

4. In a rotary printing machine according to claim 3 having in addition mechanisms on both end faces of said cylinder on the outside of said bearer rings with each of said mechanisms being operatively connected with an independent section for adjustment of both the circumferential and lateral register setting of said plates. 

1. In a rotary printing machine, a plate cylinder for substantially thin flexible printing plates of various sizes, said cylinder having end faces, said plates having a head end and a tail end, said cylinder comprising: first adjustable means axially extending of said cylinder for holding said head ends of said plates, said first means comprising at least two independent parts, second movable means axially extending of said cylinder for holding said tail ends of said plates, said second means comprising a plurality of independent sections in a side by side arrangement, a spring-loaded over-center movable linkage on each one of said independent sections for tensioning of said printing plates around the periphery of said cylinder and a rotatable shaft axially extending of said cylinder for mounting said independent sections thereon by keys and for moving simultaneously said plurality of said independent sections from a starting position over the center of said linkage to the plate tensioning position, and a third part of said first means intermediate said two independent parts and releasable clamping collars on said parts for coupling the latter together.
 2. In a rotary printing machine, a plate cylinder for substantially thin flexible printing plates of various sizes, said cylinder having end faces, said plates having a head end and a tail end, said cylinder comprising: first adjustable means axially extending of said cylinder for holding said head ends of said plates, said first means comprising at least two independent parts, second movable means axially extending of said cylinder for holding said tail ends of said plates, said second means comprising a plurality of independent sections in a side by side arrangement, a spring-loaded over-center movable linkage on each one of said independent sections for tensioning of said printing plates around the periphery of said cylinder and a rotatable shaft axially extending of said cylinder for mounting said independent sections thereon by keys and for moving simultaneously said plurality of said independent sections from a starting position over the center of said linkage to the plate tensioning position, and each of said independent sections having a circumferentially enlarged keyway therein for permitting each one of said sections to rotate freely on said shaft through a substantially small angle for enabling said over-center linkage to move each one of said sections under said spring load for tensioning said flexible printing plates held on said sections.
 3. In a rotary printing machine having a plate cylinder with end faces and bearer rings on said faces, said plate cylinder adapted to support thin flexible printing plates of various sizes where each of said plates has a head end and a tail end and where said cylinder coMprises: first rotatably adjustable plate holding devices having at least two independent sections extending axially of said cylinder for holding the head ends of said plates and by which the position of said head ends may be adjusted in circumferential and lateral directions with respect to said cylinder, second rotatably movable plate holding devices extending axially of said cylinder for holding the tail ends of said plates where said second devices comprises: a plurality of independent individual members mounted on a common axially extending rotatable shaft in side by side arrangement, key means connecting said members to said common shaft so as to allow independent rotation thereof, a spring-loaded over-center movable linkage on each one of said independent members for tensioning said printing plates around the periphery of said cylinder whereby rotation of said common shaft will move said members together from a starting position over the center of said linkages to the plate tensioning position.
 4. In a rotary printing machine according to claim 3 having in addition mechanisms on both end faces of said cylinder on the outside of said bearer rings with each of said mechanisms being operatively connected with an independent section for adjustment of both the circumferential and lateral register setting of said plates. 